Unlimited Email Tracker
Mailtrack.io
EmailTracker.cc
mTracker
Email Tracker
Saleshandy
EmailTrackerPro
Mailcastr
Followup.cc
FollowUpThen
Gmelius
Boomerang for Gmail
Right Inbox
Onesheet CRM
SendRecurring
Mailbutler
Unlimited Email Tracker Followup.ccFollowup.cc might be a bit more popular than Unlimited Email Tracker. We know about 1 link to it since March 2021 and only 1 link to Unlimited Email Tracker. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Snov.io is a free Gmail extension that can track when an email is opened, an attachment is viewed, and a link is clicked, and you can toggle each of these on/off. Source: about 3 years ago
I'll update this if I find more. For now, this seems to be a partial solution. It's a Gmail add on (except I don't use Gmail) that adds reminders. The options when setting reminders include cancelling it if someone replies, and to remind everyone in the thread. If you combine those two, it seems like — if you use Gmail's web client and have $23/month you're dying to get rid of — a decent way to add the feature. Source: over 1 year ago
Mailtrack.io - The best email tracking solution I've found. Free
FollowUpThen - The simplest way to schedule an email reminder
EmailTracker.cc - Free Email Tracker for Gmail. Close More Deals with Comprehensive Email Tracking, Automated Follow-up Reminders, and Detailed Click Insights
Gmelius - Gmelius is the first collaboration platform designed for G Suite and your company's daily tools.
mTracker - Here at MotionVFX, we try to make your lives easier.
Boomerang for Gmail - Boomerang for Gmail is a Firefox / Chrome plugin that lets you take control of when you send and receive email messages.